That saying is a reminder that there's no guarantee of a good night's sleep just because you're ready to hit the sack.

Which is unfortunate, because you need sleep to recharge your body and your mind so you can feel good the next day.

According to the National Sleep Foundation, the average person requires seven hours of restful sleep every 24 hours.

Those Sleep Foundation people need to wake up!

The hard reality is your sleep is full of interruptions. And even when you can piece together what fragmented sleep you manage to get, seven hours is almost impossible.

The first of many problems is that the three basic sleeping positions are flawed:

The "dead body" position has the sleeper lifeless on their back — until they're awakened by their own ear-shredding snore from the stuttered air intake across their flapping tonsils.

The "blade" position has the sleeper on their side — until they're awakened by a numbed arm having lost circulation under the weight of their body.

The "belly flop" position has the sleeper face down — until they're awakened by a painful crick in their neck.

Then, if you sleep next to someone else, you have to contend with their disastrous sleeping habits:

Like the bed mate who steals the covers, chilling you into snatching them back.

Like the bed mate who talks in their sleep, freaking you out with mutated sentences like, "The pencil ate my groundhog" and "Jasper sold his submarine."

Like the bed mate who jostles the mattress upon returning from the bathroom, where they just orchestrated a cacophony of offensive splashing sounds.

Like the bed mate who floods your eyes with a bedside light so they can search for something of dubious importance.

And then there is the notorious "bad dream" that wakes you up wondering whether you really did forget to complete that high school math class, whether you really did just talk to a dead relative or whether you really did just have sex with a family friend.

What a nightmare!

Plus, let's also not leave out the thunderclap that rocks the house, the frightened child who climbs into your bed or the neighbor whose booming stereo assaults your ears.

Yes, it may be bedtime. But someone or something is going to crash your slumber party.

Rob McKenzie is a professor of communication studies at East Stroudsburg University.